Patches to be applied to the skin for the purpose of, e.g., protecting the affected part and adhesive preparations to be applied to a surface of the skin of a mammal for the purpose of percutaneously administering a drug to the mammal have hitherto been developed.
Such a patch generally includes a backing, a pressure-sensitive adhesive layer laminated on at least one side of the backing, and a release liner which protects the pressure-sensitive adhesive surface of the pressure-sensitive adhesive layer. When such a patch is used, the release liner is peeled off and removed. In some patches, the release liner has a cut line in a surface thereof so as to facilitate the peeling of the release liner. The user utilizes the cut line for securing a hold for peeling off the release liner by pinching the cut areas with fingers to peel off the release liner.
WO 00/69422 pamphlet describes a patch having a release liner in which the release liner can be made easily peelable by forming a cut line of a given shape on a surface of the release liner. However, this patch has such a drawback that components of the pressure-sensitive adhesive layer may protrude from or flow out through the cut line and adhere to inner surfaces of the package in which the patch is placed, whereby it might become difficult to take the patch out of the package or the components of the pressure-sensitive adhesive layer may adhere to the hand of the user to give an uncomfortable feeling.
Techniques for avoiding the adhesion of components of the pressure-sensitive adhesive layer to the inner surface of the package include, for example, the following technique. JP-T-10-511330 (the term “JP-T” as used herein means a published Japanese translation of a PCT patent application) discloses a patch package structure in which a patch 1 having a release liner 3 is placed in a blister pack 12 and sealed with a sheet material 14. This patch package structure is shown in FIG. 10. The release liner 3 of the patch 1 has, formed on a surface thereof, a cut line 9 supporting the peel-off of the release liner. It is disclosed that this patch package structure has a given shape so that, even if components of the pressure-sensitive adhesive layer protrude from an edge of the patch 1, the components are less apt to adhere to the inner surfaces of the package.
However, since the cut line 9 of the patch can freely come into contact with the sheet material 14 in this package structure, there is a fear that, when components of the pressure-sensitive adhesive layer protrude from the cut line 9, then the components may adhere to an inner surface of the package to make it difficult to take out the patch or may adhere to the hand of the user to give an uncomfortable feeling.
Furthermore, in these documents, no statement can be found concerning the necessity of inhibiting components of the pressure-sensitive adhesive layer which have protruded from or flowed out through the cut line on a surface of the release liner from adhering to an inner surface of the package.
Recently, soft pressure-sensitive adhesive layers such as those holding a large amount of a liquid component therein tend to be employed for the purpose of improving a soft wear feeling during wear of the patch or the purpose of reducing the skin irritation caused by separation of the horny layer upon stripping of the patch. Further, with regard to adhesive preparations in which the pressure-sensitive adhesive layer contains a drug, a pressure-sensitive adhesive layer having a larger thickness has been frequently employed in recent adhesive preparations so that the pressure-sensitive adhesive layer can hold a large amount of a drug. As described above, in such cases where the pressure-sensitive adhesive layer contains a large amount of a liquid component or the pressure-sensitive adhesive layer is thick, the problem described above is apt to be actualized. Consequently, there has been a strong desire for a patch package structure in which a patch can be easily taken out of the package and can be comfortably used.